Neuro- 28A Flashcards
The four functions of the thalamus
- sensory relay
- except for olfaction
- preconscious perception of crude pain - motor feedback relay
- from the basal ganglia & cerebellum
- nuanced and accurate control of movement - reticular activating system array
- limbic relay- mammillary bodies to cingulate gyrus
The job of the hypothalamus
- detector and controller of basic drives
- thirst, hunger, sex, temperature, circadian rhythm (SCN)
Types of responses by the hypothalamus to maintain homeostasis
- neuroendocrine: control of the pituitary gland
- neurological: connections to limbic system and ANS
Connect the hypothalamic hormone to pituitary hormone release
- corticotropin-releasing hormone
- gonadotropin-releasing hormone
- growth hormone-releasing hormone
- thyrotropin-releasing hormone
- adrenocorticotropic hormone ACTH
- FSH & LH
- GH
- TSH & Prolactin
Which hypothalamic hormones are released from the posterior pituitary
- oxytocin
- vasopressin/ADH
What is prolactin inhibiting hormone?
-dopamine: inhibits prolactin release
What is Sheehan’s syndrome?
-postpartum anterior hypopituitarism
Match the hormone deficiency with symptom
- cold intolerance
- polydipsia and polyuria
- erectile dysfunction with decreased testicular volume
- fatigue and anorexia
- TSH
- ADH
- LH/FSH
- TSH or ACTH
What is Foster Kennedy Syndrome
Tumor that
- compresses one optic nerve- unilateral visual field loss
- increases intracranial pressure- papilledema in opposite eye (ICP)
- places pressure on olfactory bulb- anosmia
Causes of anosmia
- tumors of the frontal lobe
- meningitis
- trauma
Describe visual anatomy from eyes to visual cortex
optic nerves
=========optic chiasm================================
optic tracts
=======================lateral genicuate nuclei=========
optic radiations
What is the thalamic relay for the optic tract?
lateral geniculate nucleus
2 common causes of optic neuritis (visual loss)
- multiple sclerosis (adults)
- conversion disorder (adolescents)
Match visual symptom with level of lesion:
- unilateral visual field loss
- bitemporal hemianopsia
- homonomous hemianopsia
- homonymous quandrantanopsia
- optic nerve (ipsilateral)
- optic chiasm
- optic tract (contralateral)
- optic radiations (contralateral)
Which cranial nerves are responsible for extraocular movements?
-Cranial nerves 3 (medial), 4 (inferior), 6 (lateral)
Characteristics of 3rd Nerve Palsy
“Third nerve palsy leaves you
BIG (dilated pupil)
DOWN (ipsilateral lid ptosis) &
OUT (abducted/pulled to the side)”
Emergencies to consider with acute third nerve palsy
- ischemic stroke
- compression: aneurysm, herniation (between the posterior and superior cerebral artery)
Signs of third nerve palsy with contralateral hemiparesis is indication of
-MIDBRAIN INFARCT (at level of cerebral peduncle)
Characteristics of fourth nerve palsy
-head tilted away from the lesion to minimize diplopia
-diplopia is worse with reading or walking down stairs
“My neck is sore from cranial nerve 4”
Characteristics of sixth nerve palsy
-limited abduction on the ipsilateral side (diplopia present upon ipsilateral lateral gaze)
Signs of sixth nerve palsy with contralateral hemiparesis
-PONTINE INFARCT (at level of middle cerebellar peduncles)
What is the clinical trial of Horner’s Syndrome
-miosis, ptosis, anhydrosis
What is the other name for Horner’s Syndrome
-Oculosympathetic Paresis
What is the concern about Horner’s Syndrome
- disruption of sympathetic innervation ipsilateral to signs
- etiologies (EXAM)
- Pancoast tumor
- internal carotid artery dissection
Important step in the identification of Horner’s Syndrome
MRI/MRA of the head and neck
